The deadly bacteria that killed 12 New Yorkers is back in the places the city disinfected

An outbreak of a deadly bacteria in the Bronx left 12 dead and
120 sick earlier this summer.

And now, it looks like at least some of the cooling
towers that had been disinfected during the first outbreak are
now responsible for another outbreak that's
killed one and sickened 12.

That time, in late July and early August, the bacteria had been
found in the
Opera House Hotel.

Now, officials have found it in 15 out of 35 tested cooling
towers in the Morris Park section of the Bronx, northeast of the
original outbreak. The contaminated towers were in the Albert
Einstein College of Medicine, the Bronx State Psychiatric, and
Calvary Hospital, along with a few other locations.

At the time of the initial outbreak, New York City
health officials mandated that all cooling towers in the
South Bronx be disinfected to stop the spread
of Legionella bacteria, the cause of Legionnaires'
disease. But when they re-tested after the most recent outbreak
in late September, they found that the bacteria had
regrown.

According to at least one expert, this sort of thing is
rare, but not unheard of.

“Nine out of 10 times, the disinfection will be
effective,” Tim Keane, a consulting engineer at
Legionella Risk Management Inc.
told the New York Times. “But if the treatment program
and risk management program isn’t in place after the
disinfection, nine out of 10 times the bacteria will regrow again
if it was there before.”

Legionnaires' is not spread by person-to-person
contact; the bacteria
thrive in infected water, and especially in mist. In recent
cases, researchers have linked the outbreak to the cooling towers
used in the air-conditioning systems of hospitals, along with
whirlpool spas and grocery-store misters. It can be treated with
antibiotics.

People with existing health conditions are more susceptible
to Legionnaires'. All of the people who have died from the first
outbreak were older adults who were sick before picking up
the bacteria. This time around, all of the people who have fallen
ill thus far have had pre-existing health conditions.